BYD ATTO 3 (e-Platform 3.0) B2ABB17 AC Compressor High-Voltage Side Overvoltage Fault

B2ABB17 indicates that an overvoltage condition has been detected on the high-voltage side of the electric A/C compressor. The fault affects the compressor’s high-voltage power supply and drive electronics, which regulate electrical power to operate the compressor motor and maintain refrigerant circulation for cabin cooling. The BYD ATTO 3 uses BYD’s e-Platform 3.0 architecture, with this generation introduced from 2022 and continuing onward.

Symptoms

• Air conditioner does not produce cold air
• Electric compressor fails to start
• A/C cooling may stop unexpectedly
• Compressor may shut down as a protective measure
• Climate control warning may be displayed
• Cabin temperature remains higher than requested
• High-voltage HVAC fault codes may be stored
• Compressor operation may be intermittent

Possible Causes

• Excessive high-voltage supply to the A/C compressor
• High-voltage battery or power-management fault
• Compressor inverter overvoltage condition
• DC high-voltage supply regulation fault
• Damaged high-voltage compressor wiring
• Poor or loose high-voltage connector connection
• Internal compressor power-electronics fault
• Electrical transient or abnormal voltage event
• Fault in the high-voltage distribution system
• Low-voltage control-system fault affecting compressor operation
• Compressor control-module fault
• Thermal-management or protection-system intervention

Diagnosis

Diagnosis should begin by confirming B2ABB17 and checking for related high-voltage battery, power-distribution, compressor, and electrical-system faults.

High-voltage supply data, compressor operating status, voltage measurements, connector condition, wiring integrity, and relevant control-module parameters should then be evaluated against manufacturer specifications.

The diagnostic direction should establish whether the overvoltage originates from the vehicle high-voltage supply, wiring, compressor power electronics, or control system before replacing components. Because the A/C compressor operates on the vehicle’s high-voltage system, manufacturer isolation procedures and appropriate EV safety equipment are essential during diagnosis.

For New Zealand owners, confirming the source of the overvoltage before replacing high-voltage HVAC components can help avoid unnecessary repair costs.

Accurately diagnosing this fault often requires manufacturer testing procedures, wiring diagrams, connector pinouts, specifications, and system calibration information. Access to the factory service manual significantly reduces diagnostic time and helps prevent unnecessary parts replacement.

Applicable Years

2022, 2023, 2024, 2025, 2026, Onwards

To order the correct OEM Service and Repair Manual for your BYD ATTO 3, submit your request using the form below and our team will provide the ordering details.